(define (solve)
  (define (step n k)
    (cond ((= n 3) k)
          ((even? n) (step (/ n 2) (+ 1 k)))
          (else (step (* 3 (+ 1 n)) (+ 1 k)))))
  (define (max-step m n)
    (if (zero? n) m
        (let ((s (step n 0)))
          (max-step
           (if (< (car m) s) (cons s n) m)
           (- n 1)))))
  (max-step (cons 0 0) 10000)
  )

(display "(step . n) = ")
(display (solve))
(newline)